Draw a tile as usual. This time, it shows a castle. There is also a road that ends at the castle. As usual, you must make sure all edges match when adding the land tile to the board.
You may place a meeple onto the castle instead of the road. As usual, you may only place 1 meeple.
Score the castle as soon as it is completely surrounded by land tiles. Score 2 points for each surrounding tile with mist on it (including the castle tile itself).
Hurray! When one of your fellow players places this tile, your castle is completely surrounded. Scoring will occur at the end of their turn. There are a total of 5 tiles with mist on them around the castle, plus the castle tile itself. You score 12 points and return your meeple to your supply.